Assignment of the 1H and 15N NMR Spectra of Rhodobacter capsulatus Ferrocytochrome c2

Abstract

The peptide resonances of the 1H and 15N nuclear magnetic resonance spectra of ferrocytochrome c2 from Rhodobacter capsulatus are sequentially assigned by a combination of 2D 1H-1H and 1H-15N spectroscopy, the latter performed on 15N-enriched protein. Short-range nuclear Overhauser effect (NOE) data show α-helices from residues 3-17, 55-65, 69-88, and 103-115. Within the latter two α-helices, there are three single 310 turns, 70-72, 76-78, and 107-109. In addition αH-NH,+1 and αH-NH,+2 NOEs indicate that the N-terminal helix (3-17) is distorted. Compared to horse or tuna cytochrome c and cytochrome c2 of Rhodospirillium rubrum, there is a 6-residue insertion at residues 23-29 in R. capsulatu..